System and method for detecting neurological disorders and for measuring general cognitive performance

ABSTRACT

Methods and systems useful for detecting neurological disorders and for measuring general cognitive performance, in particular by measuring eye movements and/or pupil diameter during eye-movement tasks.

FIELD OF THE INVENTION

The invention relates to systems and methods for detecting neurological disorders and for measuring general cognitive performance, in particular by measuring eye movements and/or pupil diameter during eye-movement tasks.

BACKGROUND TO THE INVENTION

Using eye tracking as a diagnostic tool has been implemented in the art:

U.S. Pat. No. 4,889,422 discloses an automated system for determining the existence of dyslexia. The system comprises an eye stimulus means, an eye movement detector, a processor that collects data representing eye positions over time, and an analysis program for analyzing the data and categorizing the eye movements into micromovements, saccade movements, pursuit movements, convergent divergent movements, fixations and blinks. If the total number of fixations is greater than the number of visual stimuli, then a first indicator that dyslexia is present is registered.

Fielding et al published “Ocular motor measures of cognitive dysfunction in multiple sclerosis II: working memory” (J Nerol, published online 9 Apr. 2015), which discloses an experiment in which working memory of patients with clinically-definite multiple sclerosis (CDMS) or clinically isolated syndrome (CIS) were tested for working memory by an ocular test which measured task errors, saccade latency, and relative sensitivity to loading of working memory

There is a long felt need for a widely availability tool for diagnosing neurological disorders.

SUMMARY OF THE INVENTION

It is the object of the present invention to provide a system for detecting one or more neurological disorders in a subject by measuring eye movements; the measuring of eye movements performed while the subject is reading; the system comprising

-   -   a. an eye tracker [10], configured to monitor eye movements of a         subject [5] while the subject [5] is reading a text [15];     -   b. a processor [20], configured to receive data from the eye         tracker [10] while the subject [5] is reading the text [15]; and     -   c. a display means [40] configured to display a test report [50]         received from the processor [20];         wherein the processor [20] is further configured to analyze the         eye-tracking data for evidence of one or more neurological         disorders or general cognitive performance and to report, in the         test report [50], a detection of one or more neurological         disorders or a measure of cognitive performance of the subject         [5].

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to:

-   -   a. count a total number of ocular fixations of a subject while         reading the text; and     -   b. if the total number of ocular fixations of a subject when         reading is higher than for a control group, then report in the         test report that a compromise in attentional processes is         detected.

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to:

-   -   a. count a number of forward ocular fixations of the subject         while reading the text; and     -   b. if the number of forward ocular fixations of the subject is         lower than for the control group; and the number of ocular         fixations of a subject when reading is higher than for the         control group, then report in the test report [50] that a         compromise in working memory is detected.

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to:

-   -   a. count a number of words that the subject fixated on only once         while reading the text; and     -   b. if the number of words that the subject fixated on only once         is lower than for the control group, then report in the test         report that a compromise in retrieval memory is detected.

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to:

-   -   a. count a number of multiple ocular fixations of the subject         while reading the text; and     -   b. if the number of multiple ocular fixations is higher than for         the control group, then report in the test report that a         compromise in executive processes is detected.

It is another object of the present invention to detecting one or more neurological disorders in a subject by measuring eye movements, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to

-   -   a. compute an average saccade amplitude from one ocular fixation         to a next ocular fixation; and     -   b. if the average saccade amplitude is lower than for the         control group, then report in the test report that a compromise         in executive processes is detected.

It is another object of the present invention as described above, further comprising a means [17] for measuring a pupil diameter of the subject, wherein the processor is further configured to

-   -   a. track the pupil diameter of the subject reading the text; and     -   b. if the pupil diameter of the subject does not show a         reduction as advancing in reading the text, then report in the         test report that that a compromise in executive processes is         detected.

It is the object of the present invention to provide a system for detecting one or more neurological disorders and to check cognitive performance in a subject by measuring eye movements and pupil behavior and applying an intelligent algorithm; the measuring of eye movements performed while the subject is reading; the system comprising

-   -   a. an eye tracker [10], the eye tracker configured to monitor         eye movements and pupil behavior of a subject [5] while the         subject [5] is reading a text [15];     -   b. a processor [20], the processor configured to receive data         from the eye tracker [10] while the subject [5] is reading the         text [15];     -   c. an intelligent algorithm for learning, identifying, typifying         and classifying eye movements features in pathologies and within         pathologies; and     -   d. a display means [40], the display configured to display the         output of the intelligent algorithm on a test report [50]         received from the processor [20];         wherein the processor [20] is further configured to analyze and         modeling the eye-tracking data for evidence of one or more         neurological disorders and from cognitive performance and to         report, in the test report [50], a detection and classification         of the one or more neurological disorders of the subject [5]         both, between and within pathologies.

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to identify and classifying eye movement features and pupil behavior during reading the text providing an output of the classifier for reporting in the test report a subject's cognitive performance and/or pathological classification (i.e, the pathology that correspond to the subject because his/her eye movement features); and a value within the pathology (i.e., the level of cognitive, behavioral and biological compromise that the subject shows within a particular pathology).

It is another object of the present invention as described above, wherein the intelligent algorithm is configured to read at least one input, the input selected from a group consisting of:

-   -   a. Index of total number of ocular fixations of a subject while         reading the text.     -   b. Index of forward ocular fixations of the subject while         reading the text.     -   c. Index of words that the subject fixated on only once while         reading the text     -   d. Index of multiple ocular fixations of the subject while         reading the text     -   e. Average saccade amplitude from one ocular fixation to a next         ocular fixation     -   f. Pupil diameter of the subject reading the text     -   g. Index of blinks coming from the left eye, the right eye or         from both eyes.     -   h. Microsaccades' Factors of Form (FF):         -   i. HEWI: shows the micro-saccade's height/width             relationship.         -   ii. AREA: shows the area of the rectangle in which the             micro-saccade is inscribed.         -   iii. LONG: is the longitude of the horizontal-vertical plane             trajectory of the micro-saccade.         -   iv. ANG: is the sum of all the angles in the plane             horizontal-vertical plane of the micro-saccade.         -   v. AANG: is the sum of all the absolute values of angles in             radians in the plane horizontal-vertical plane of the             micro-saccade. These last two FF gives an estimation of the             micro-saccadic trajectory regularity.         -   vi. MOD and THETA: are the modulus and the angle of the             polar coordinates of the sum of the cartesian coordinates.             They give a spatial orientation of the micro-saccade             relative to the median of the fixation.         -   vii. TIME: is the time duration in milliseconds of the             micro-saccade.         -   viii. VMIN and VMAX: are the minimum and maximum velocities             of the microsaccades in degrees per second.         -   ix. Micro-saccade rate: is the instantaneous rate in each             time bin.         -   x. Directional congruency: is the congruency between the             micro-saccade direction and the location of the stimulus.     -   i. Eye position coming from the left eye, the right eye or from         both eyes (i.e., abscissa and ordinate coordinate) during         reading the text.     -   j. Fixation sequence (i.e., ocular behavior) during reading the         text. The sequence will be available from images, from matrices,         etc.     -   k. Distance of separation between ocular fixations during         reading the text.     -   l. Filia information of the subject (i.e., age; years of         education; sex; ethnic group; occupation; hours per week of         physical activity).     -   m. Total reading time (i.e., the time that the subject spent         when reading the text).

It is the object of the present invention to provide a method [300] for evaluating compromises in neurological functions associated with Multiple Sclerosis [MS], the method comprising

-   -   a. providing a system for evaluating compromises in neurological         functions associated with MS [305];     -   b. requesting a subject to fixate on a reference target of a         chart [310];     -   c. for a number of repetitions, presenting a stimulus image in         one of the zones to the subject [315]; the subject is requested         to remember which zone each stimulus image appeared and in what         order;     -   d. presenting to the subject a cue corresponding to one of the         presented stimulus images [320];     -   e. measuring a saccade of the subject [325] in response to the         step of presenting a cue; the subject is requested to look at         the zone in which the stimulus image was the presented         corresponding to the cue;     -   f. repeating steps of presenting a cue and measuring a saccade         [330];     -   g. repeating steps b-f for a number of trials [335];     -   h. calculating one or more of:         -   i. a WM effect [340] (i.e. WM effect is a measure that             increases when WM demand increases. For each cue number, the             WM effect is represented by the ratio between the number of             errors reported by the subject through all the trials, and             the number of trials); and         -   ii. an average saccadic latency [345], saccadic latency             defined as an amount of time for the subject to initiate a             saccade to the zone; and     -   i. reporting one or more of:         -   i. a degree of compromise in working memory [350], with             increased WM effect; and         -   ii. a degree of compromise in executive processes [355],             with increased saccadic latency;     -   j. wherein the method further comprises additional steps         comprising measurements performed during the step of presenting         a stimulus image [315], during which the subject is further         requested to look at the stimulus image; the measurements         comprising measuring one or more of         -   i. an amplitude of pupillary dilatation of the subject             [360];         -   ii. a number of fixations made by the subject on the             stimulus image [365]; and         -   iii. a gaze duration by the subject on the stimulus image             [370]; and     -   k. the additional steps further comprising calculating and         reporting one or more of         -   i. a degree of compromise of subcortical processes [375],             with increased the amplitude of pupillary dilatation;         -   ii. a degree of compromise of executive processes [380],             with increased the number of fixations; and         -   iii. a degree of compromise of executive processes and             working memory [385], with increased the gaze duration.

It is another object of the present invention as described above, wherein the reference target is at a central position of the chart and the plurality of zones are disposed around the reference target.

It is another object of the present invention as described above, wherein the cue is disposed at a position of the reference target.

It is another object of the present invention as described above, wherein the errors defined as eye movement towards a location other than the correct zone and/or no saccade initiated within a time limit.

It is another object of the present invention as described above, wherein a cue corresponding to a first presented stimulus is excluded from the presented cue numbers.

It is another object of the present invention as described above, wherein a saccade is included in the step of calculating the WM effect and the saccadic latency only if the saccade is initiated more than a minimum saccade latency after the step of presenting the cue number.

It is another object of the present invention as described above, wherein the saccade is excluded from calculating WM if: no saccade to one of the zones is made within a time limit, failing to maintain the fixation on the reference target before onset of a saccade to one of the angular zones, and blinking causing eye motion to be indeterminate

It is the object of the present invention to provide a system for detecting one or more neurological disorders in a subject by measuring eye movements; the measuring of eye movements performed while the subject is carrying out the visual test; the system comprising

-   -   a. an eye tracker [10], configured to monitor eye movements of a         subject [5] while the subject [5] is carrying out the visual         test [15];     -   b. requesting a subject to fixate sequentially on targets that         are part of a group of targets (e.g., point) presented together         in the same picture (i.e., labyrinth or maze) [605];     -   c. requesting a subject to fixate only one target each time         until finishing visualizing all the targets through the picture         following the labyrinth or maze direction (i.e., entering from         the bottom and exiting through the top of said labyrinth or         maze) [610]     -   d. a processor [20], configured to receive data from the eye         tracker [10] while the subject [5] is carrying out the visual         test [15]; and     -   e. a display means [40] configured to display a test report [50]         received from the processor [20];         wherein the processor [20] is further configured to analyze the         eye-tracking data for evidence of neurological and attentional         disorders and to report, in the test report [50], a detection of         the one or more neurological and attentional disorder of the         subject [5].

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker while the subject is visualizing, recognizing, maintaining, controlling, inhibiting and sequencing targets, to:

-   -   a. count a total number of ocular fixations of a subject [615]         while performing the visual test; and     -   b. if the total number of ocular fixations of a subject when         visualizing targets is higher than for a control group, then         report in the test report that a compromise in attentional         processes is detected.

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to:

-   -   a. measure the saccade average speed [620] while the subject is         shifting from one target to the other; and     -   b. if the saccade average speed [620] of the subject is lower         than for the control group; then report in the test report [50]         that a compromise in executive functions is detected.

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to:

-   -   a. count a number of correct target recognitions [625]; and     -   b. if the number of correct target recognitions [625] that the         subject is lower than for the control group, then report in the         test report that a compromise in working memory is detected.

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to:

-   -   a. compute an average saccade amplitude [630]; and     -   b. if the average saccade amplitude [630] is lower than for the         control group, then report in the test report that a compromise         in executive processes is detected.

It is another object of the present invention as described above, wherein the processor is further configured, upon receiving the eye-tracking data from the eye tracker, to:

-   -   a. the total time spent to perform the visual test [635]; and     -   b. if the total time spent to perform the visual test [635] is         higher than for the control group, then report in the test         report that a compromise in attentional processes is detected.

It is another object of the present invention as described above, further comprising a means [17] for measuring a pupil diameter of the subject, wherein the processor is further configured to:

-   -   a. track the pupil diameter of the subject [640] performing the         visual test; and     -   b. if the pupil diameter of the subject [640] does not show an         increase when advancing in performing the task, then report in         the test report that that a compromise in attentional processes         is detected.

It is another object of the present invention as described above, further comprising a means [17] for measuring a pupil diameter of the subject, wherein the processor is further configured for calculating fixation durations on targets of person while performing the visual test, if the fixation duration of the subject [645] while fixating on targets is lower than for the control group, then report in the test report that that a compromise in attentional and executive processes is detected.

It is the object of the present invention to provide a method [400] for detecting the presence of one or more neurological disorders or for measuring general cognitive performance in a subject by measuring eye movements of the subject; the measuring of eye movements performed while the subject is reading [405]; the method comprising steps of:

-   -   a. providing the system for detecting one or more neurological         disorders of claim 1 or claim 18;     -   b. receiving eye-tracking data and/or pupil diameter data of a         subject while the subject is reading a text [415];         wherein the method further comprises steps of analyzing the         eye-tracking data and/or pupil diameter data for evidence of one         or more neurological disorders [417] and displaying a report of         a detection of the neurological disorder(s) [4Fi99].

It is another object of the present invention as described above, further comprising steps of:

-   -   a. counting a total number of ocular fixations of the subject         while the subject is reading the text [420]; and     -   b. if the total number of ocular fixations of the subject while         reading the text is higher than for a control group, then         reporting that a compromise in attentional processes is detected         [460].

It is another object of the present invention as described above, further comprising steps of:

-   -   a. counting a total number of ocular fixations of the subject         while the subject is reading the text [420];     -   b. counting a number of forward ocular fixations of the subject         while the subject is reading the text [430]; and     -   c. if the number of forward ocular fixations of the subject         while reading the text [430] is lower than for the control         group; and the number of ocular fixations of a subject when         reading is higher than for the control group, then reporting         that a compromise in working memory is detected [470].

It is another object of the present invention as described above, further comprising steps of:

-   -   a. counting numbers of ocular fixations by the subject on each         word in the text while the subject is reading the text [440];     -   b. counting a number of the words that the subject fixated on         only once while reading the text [445]; and     -   c. if the number of words that the subject fixated on only once         while reading the text [445] is lower than for the control         group, then reporting that a compromise in retrieval memory is         detected [480].

It is another object of the present invention as described above, further comprising steps of:

-   -   a. counting a number of multiple ocular fixations of the subject         while reading the text [450]; and     -   b. if the number of multiple ocular fixations of the subject         while the subject is reading the text [450] is higher than for         the control group, then reporting that a compromise in executive         processes is detected [490].

It is another object of the present invention as described above, further comprising steps of:

-   -   a. computing an average saccade amplitude of the subject from         one ocular fixation to a next ocular fixation while reading the         text [454]; and     -   b. if the average saccade amplitude of the subject from one         ocular fixation to a next ocular fixation while reading the text         [454] is lower than for the control group, then reporting in the         test report that a compromise in executive processes is detected         [491].

It is another object of the present invention as described above, further comprising steps of:

-   -   a. tracking a pupil diameter of the subject reading the text         [456];     -   b. if the pupil diameter of the subject reading the text [456]         does not show a reduction as advancing in reading the text, then         reporting in the test report that a compromise in executive         processes is detected [492].

It is the object of the present invention to present a system [100] for detecting a disorder of memory binding function of a subject, the system comprising:

-   -   a. an eye tracker [10];     -   b. a means for measuring pupil diameters;     -   c. a processor [20], configured to:         -   i. receive eye-tracking data of a subject [5] from the eye             tracker [10];         -   ii. receive pupil diameter data of the subject [5] from the             means for measuring pupil diameters; and     -   d. a display means [40] configured to display a test report [50]         received from the processor [20];         wherein the processor [20] is further configured to analyze the         eye-tracking and pupil diameter data and to report, in the test         report [50], a detection of one or more disorders of memory         binding function of the subject [5].

It is another object of the present invention as described above, wherein the processor [20] is further configured, upon receiving the eye-tracking data from the eye tracker [10], to:

-   -   a. measure one or more gaze durations of the subject [5] on each         of one or more targets viewed by the subject [5];     -   b. calculate an average gaze duration of the targets by the         subject [5]; and     -   c. report in the test report [50] that a compromise in encoding         and recognition of targets is detected in the subject [5], if         the average gaze duration of the subject [5] is longer than the         average gaze duration of a control group.

It is another object of the present invention as described above, wherein the processor [20] is further configured, upon receiving the eye-tracking data from the eye tracker [10], to:

-   -   a. count a number of ocular fixations performed by the subject         [5] while viewing one or more targets; and     -   b. report in the test report [50] that a compromise in         attentional processes is detected in the subject [5], if the         number of ocular fixations performed by the subject [5] while         viewing the targets is higher than for a control group.

It is another object of the present invention as described above, wherein the processor [20] is further configured to applying an intelligent algorithm and to:

-   -   a. receive a pupil diameter of the subject [5] from the means         for measuring pupil diameter, while the subject [5] performs         activities requiring lower cognitive effort;     -   b. receive a pupil diameter of the subject [5] from the means         for measuring pupil diameter, while the subject [5] performs         activities requiring a stronger cognitive effort; and     -   c. report in the test report [50] that a compromise in cognitive         resources is detected in the subject [5], if the pupil diameter         of the subject [5], while performing the activities requiring         the stronger cognitive effort, does not show an increase over         the pupil diameter of the subject [5] while performing the         activities requiring reduced/minimal cognitive effort.

It is another object of the present invention as described above, wherein the processor [20] further reports a result in the test report [50], for the disorder of memory binding function not detected by the system [100] in the subject [5].

It is the object of the present invention to provide a method [500] for detecting a disorder of memory binding function of a subject [505], the method comprising steps of:

-   -   a. providing a system of claim 1 or claim 33;     -   b. Presenting targets [510];     -   c. Requesting a subjects to fixate on targets and to remember         them (Encoding) [515];     -   d. Presenting an empty screen [520];     -   e. Presenting targets and requesting a subject to identify if         the targets are exactly the same that were viewed before         (Recognition). If the targets are exactly the same an answer         saying “same” must be given. If are not exactly the same, an         answer saying “different must be given. Both answers must be         collected using a keyboard or similar support [525]. Repeating         steps from [510-525] for a number of trials [530];     -   f. Repeating steps [510-525] for a number of trials [530];     -   g. receiving eye-tracking data;     -   h. viewing by a subject of one or more targets [540];     -   i. measuring the gaze duration of the subject on each of the         targets [545];     -   j. calculating an average gaze duration of the targets by the         subject [550];     -   k. measuring a pupil diameter of the subject while performing         activities requiring lower cognitive effort [555];     -   l. counting a number of ocular fixations performed by the         subject while viewing the targets [560];     -   m. wherein the method further comprises steps of:         -   i. reporting that a compromise in a target encoding and             recognition process is detected in the subject, if the             average gaze duration of the subject is longer than an             average gaze duration of a control group [565];         -   ii. reporting that a compromise in cognitive resources is             detected in the subject, if the pupil diameter of the             subject while performing the activities requiring a stronger             cognitive effort does not show an increase over the pupil             diameter of the subject while performing the activities             requiring lower cognitive effort [570]; and         -   iii. reporting that a compromise in attentional processes is             detected in the subject, if the number of ocular fixations             performed by the subject while viewing the targets is higher             than for a control group [575].

It is another object of the present invention as described above, wherein the intelligent algorithm is configured to read at least one input, the input selected from a group consisting of:

-   -   a. Total number of ocular fixations of a subject while         performing each Binding Task.     -   b. Binding Evaluation Task, i.e. “Bound Colors” of “Unbound         Colors”.     -   c. Identification Number of Binding Trial.     -   d. The Correct Behavioral Answer of the trial (i.e., if “same”         or “different”).     -   e. Subject's Behavioral response.     -   f. Part of the Trial i.e., encoding or retrieval.     -   g. Pupil diameter of the subject while performing while         performing the Binding Evaluation.     -   h. Number of blinks coming from the left eye, the right eye or         from both eyes.     -   i. Microsaccades; Factors of Form (FF):         -   i. HEWI: shows the microsaccade's height/width relationship.         -   ii. AREA: shows the area of the rectangle in which the             microsaccade is inscribed.         -   iii. LONG: is the longitude of the horizontal-vertical plane             trajectory of the microsaccade.         -   iv. ANG: is the sum of all the angles in the plane             horizontal-vertical plane of the microsaccade.         -   v. AANG: is the sum of all the absolute values of angles in             radians in the plane horizontal-vertical plane of the             microsaccade. These las two FF give an estimation of the             microsaccadic trajectory regularity.         -   vi. MOD and THETA: are the modulus and the angle of the             polar coordinates of the sum of the cartesian coordinates.             They give an spatial orientation of the microsaccade             relative to the median of the fixation.         -   vii. TIME: is the time duration in milliseconds of the             microsaccade.         -   viii. VMIN and VMAX: are the minimum and maximum velocities             of the microsaccades in degrees per second.         -   ix. Microsaccade rate: is the instantaneous rate in each             time bin.         -   x. Directional congruency: is the congruency between the             microsaccade direction and the location of the stimulus.     -   j. Eye position coming from the left eye, the right eye or from         both eyes (i.e., abscissa and ordinate coordinate) while         performing the Binding Evaluation.     -   k. Saccade amplitude while processing targets.     -   l. Fixation sequence (i.e., ocular behavior) during processing         targets. The sequence will be available from images, from         matrices, etc.     -   m. Distance between the fixation point of the Right Eye and the         Left Eye while performing the Binding Evaluation.     -   n. Filia information of the subject (i.e., age; years of         education; sex; ethnic group; occupation; hours per week of         physical activity).     -   o. Fixation duration while processing targets.     -   p. Gaze duration while processing targets.     -   q. Number of fixations on each target.     -   r. Number of fixations outside each target.     -   s. Number of fixation on each target.

It is the object of the present invention to provide a method [600] for detecting a neurological and attentional disorders of a subject, the method comprising steps of:

-   -   a. providing an eye tracker [10];     -   b. a means for measuring pupil diameters;     -   c. a processor [20], configured to:         -   i. receive eye-tracking data of a subject [5] from the eye             tracker [10];         -   ii. receive pupil diameter data of the subject [5] from the             means for measuring pupil diameters; and         -   iii. a display means [40] configured to display a test             report [50] received from the processor [20];             wherein the processor [20] is further configured to analyze             the eye-tracking and pupil diameter data and to report, in             the test report [50], a detection of one or more             neurological and attentional disorders of the subject [5].

It is another object of the present invention as described above, wherein the processor [20] is further configured, upon receiving the eye-tracking data from the eye tracker [10], to:

-   -   a. measure one or more fixation durations of the subject [5] on         each of one or more targets viewed by the subject [5];     -   b. calculate an average saccade amplitude from each target to         the other one by the subject [5]; and     -   c. report in the test report [50] that a compromise in         visualizing, recognizing, maintaining, controlling, inhibiting         and sequencing of targets is detected in the subject [5], if the         average saccade amplitude of the subject [5] is shorter than the         average saccade amplitude of a control group.

It is another object of the present invention as described above, wherein the processor [20] is further configured, upon receiving the eye-tracking data from the eye tracker [10], to:

-   -   a. count a number of ocular fixations performed by the subject         [5] while viewing one or more targets; and     -   b. report in the test report [50] that a compromise in         attentional processes is detected in the subject [5], if the         number of ocular fixations performed by the subject [5] while         viewing the targets is higher than for a control group.

It is another object of the present invention as described above, wherein the processor [20] is further configured to:

-   -   a. receive a pupil diameter of the subject [5] from the means         for measuring pupil diameter, while the subject [5] performs         activities requiring major attention resources;     -   b. receive a pupil diameter of the subject [5] from the means         for measuring pupil diameter, while the subject [5] performs         activities requiring a major attention; and     -   c. report in the test report [50] that a compromise in cognitive         resources is detected in the subject [5], if the pupil diameter         of the subject [5], while performing the activities requiring         the major attention, does not show an increase over the pupil         diameter of the subject [5] while performing the activities         requiring minor attention.

It is the object of the present invention to provide a method [600] for detecting a neurological and executive disorder of a subject, the method comprising steps of

-   -   a. providing a system as described above;     -   b. receiving eye-tracking data;     -   c. viewing by a subject of one or more targets [605-610];     -   d. calculating an average saccade amplitude of the targets by         the subject [630];     -   e. measuring a pupil diameter of the subject while performing         activities requiring major attention [640];     -   f. measuring a pupil diameter of the subject while performing         activities requiring a major attention than the minor attention;         and     -   g. counting a number of ocular fixations performed by the         subject while viewing the targets [615];     -   h. wherein the method further comprises steps of:         -   i. reporting that a compromise in a target visualizing,             recognizing, maintaining, controlling, inhibiting and             sequencing process is detected in the subject, if the             average saccade amplitude of the subject is shorter than an             average saccade amplitude of a control group;         -   ii. reporting that a compromise in cognitive and functional             resources is detected in the subject, if the pupil diameter             of the subject while performing the activities requiring a             major attention does not show an increase over the pupil             diameter of the subject while performing the activities             requiring minor attention; and         -   iii. reporting that a compromise in attentional processes is             detected in the subject, if the number of ocular fixations             performed by the subject while viewing the targets is higher             than for a control group.         -   iv. reporting that a compromise in executive process is             detected in the subject, if the average saccade latency             (speed) of the subject is shorter than an average saccade             latency of a control group;

It is another object of the present invention as described above, wherein the method is configured to report that a compromise in executive process is detected in the subject, if the average saccade duration of the subject is shorter than an average fixation duration of a control group.

It is another object of the present invention as described above, wherein the neurological disorder is selected from the group consisting of Parkinson Disease or Attention Deficit Hyperactive Disorder.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 and FIG. 2 shows a system for detecting one or more neurological disorders of a subject, according to some embodiments of the invention.

FIGS. 3A and 3B show a method for evaluating compromises in neurological functions associated with MS, according to some embodiments of the invention.

FIGS. 4A and 4B show a method for detecting one or more neurological disorders of a reading subject, according to some embodiments of the invention.

FIG. 5 shows a method for detecting a disorder of memory binding function, according to some embodiments of the invention.

FIG. 5B shows the test results as per the evaluation method of 5A: Corrected recognition during the two experimental conditions in both controls and AD patients (error bars=standard errors of the mean).

FIG. 5C shows the test results as per the evaluation method of 5A: Effect of binding task on gaze duration in control and in Alzheimer Disease (AD) patients during Encoding and Recognition moments. The panel shows the partial effects of LMM (i.e., after removal of other fixed effects and variance components). Shaded areas denote 95% confidence intervals. Gaze duration is plotted on a log scale for correspondence with the LMM.

FIGS. 6A and 6B shows a method for detecting Parkinson Disorder and Attention Deficit Hyperactive Disorder

DETAILED DESCRIPTION

The term “cognitive effort” reflects the total amount of mental effort that a subject needs to perform a task. In this application, the term “lower cognitive effort” refers to a reduction on working memory demands when performing a task.

In this application, the term “Microsaccades”, also known as “flicks”, are small saccades performed during the fixation periods. They are the largest and fastest of the fixational eye movements. In this application, the term “saccades” relate to quick, simultaneous movement of both eyes between two or more phases of a fixation.

In this application the term “Ocular drift” is the fixational eye movement characterized by a smoother, slower, roaming motion of the eye when fixed on an object.

In this application the term “Ocular microtremors” (OMTs) are small, quick, and synchronized oscillations of the eyes occurring at frequencies in a range of 40 to 100 Hz, although they typically occur at around 90 Hz in the average healthy individual. They are characterized by their high frequency and minuscule amplitude of just a few arcseconds.

In this application the terms “stimulus image” refers to a specific visual pattern or targets presented to the subject in the display. The term “visual task” or “visual test” refers to the activity that performs the subject while processing each stimulus image.

Non-limiting embodiments of the invention are now described in detail.

Reference is now made to FIG. 1 , showing a system [100] for detecting a neurological disorder or neurological function of a subject [5], according to some embodiments of the invention.

System [100] comprises an eye tracker [10], a means for measuring a pupil diameter [17], a processor [20], and a display means [40].

Eye tracker [10] can be of any type known in the art; for example, an eye-attached tracker, an optical eye tracker, or an electrooculographic eye tracker.

Means for measuring pupil diameter [17] may comprise, for example, a camera configured to acquire an image of the eye and a processing unit for measuring the pupil diameter from the image. Alternatively to a processing unit, means for measuring a pupil diameter [17] can comprise a display of the image with manual measurement made while viewing the display.

Eye tracker [10] and means for measuring a pupil diameter [17] are in communicative connection with processor [20]. The communicative connections can be of any form(s) known in the art, and can be either wired (e.g., USB, parallel port, or similar) or wireless (e.g. WiFi, Bluetooth, or similar).

Processor [20] receives and executes instructions stored in one or more memory media [60], such as RAM, CD/DVD, HDD, flash memory, and/or any suitable medium. The instructions command processor [20] to: 1) receive eye-tracking data from eye tracker [10]; 2) receive pupil diameter data from means [17] of measuring pupil diameter; 3) analyze the eye-tracking and pupil diameter data (further explained herein); 4) report in a test report 50, for display on display means [40], of a detection or non-detection of one or more disorders of memory binding function in subject [5]. Display means [40] can be a monitor, a screen of a mobile device such as a smartphone, a printout, or any suitable means of displaying test report [50]. Processor [20] may store in memory medium [60] any of the received eye-tracking data, intermediate results at any stage(s) of the analysis, and/or test report [50].

Neurological disorders detected by system [100] can include reading function, such as a compromise in encoding and recognition of targets, a compromise in attentional processes, a compromise in cognitive resources, or any combination thereof. In other embodiments the disorders detected can include Multiple sclerosis (MS), Attention deficit-hyperactive disorder (ADHD), Parkinson disorder (PD), Alzheimer disease (AD), etc.

In some embodiments, processor [20] receives eye-tracking data from eye-tracker [10] while subject [5] views each of one or more targets [30]. Processor [20] measures gaze durations of subject [5] on each target [30] viewed by subject [5]. Processor [20] calculates an average gaze duration on each of the targets [30] by subject [5]. If an average of the gaze durations on targets [30] of subject [5] is longer than an average gaze duration for a control group, then processor [20] reports in test report [50] that a compromise in a target encoding and recognition process is detected in subject [5].

In some embodiments processor [20] additionally, or alternatively, counts a number of ocular fixations performed by subject [5] while viewing each of the targets [30]. If the number of ocular fixations performed by subject [5] while viewing the targets [30] is higher than for a control group, then processor [20] reports in test report [50] that a compromise in the attentional processes is detected in subject [5].

In some embodiments, processor [20] receives pupil diameter data from means [17] of measuring pupil diameter while subject [5] performs activities requiring lower cognitive effort. Processor [20] further receives pupil diameter data from means [17] of measuring pupil diameter while subject [5] performs activities requiring a stronger cognitive effort than for the activities requiring lower cognitive effort. If an average pupil diameter of subject 5 while performing the activities requiring the stronger cognitive effort does not show an increase over an average pupil diameter of subject [5] while performing the activities requiring lower cognitive effort, then processor [20] reports in test report [50] that a compromise in cognitive resources is detected in subject [5].

The control group may comprise a statistically representative cross-section in the same demographic sector as subject [5] (e.g., the same gender, race, national culture, age group, and/or other demographic features of subject [5]). Eye-tracking data for the control group may be obtained by system [100] or otherwise gathered from previous research studies and/or clinical studies. Where the average gaze duration or number of ocular fixations of subject [5] is within a selected margin—about one standard deviation of a distribution of the corresponding figure for the control group—of the average figure for the control group, system [100] may treat the average gaze duration or number of ocular fixations of subject [5] as equal to the average corresponding figure for the control group.

It is understood that eye tracking data received by processor [20] may be a series of eyeball positions measured by eye tracker [10], which processor [20] analyzes to find gaze durations and ocular fixations of subject [5]. Alternatively, processor [20] may receive a series of pre-processed signals from eye tracker [10], each signaling a gaze duration or that an ocular fixation has occurred. The signals may optionally be accompanied with metadata (e.g., eyeball position, time, and/or length of the ocular fixation).

Multiple Sclerosis

Reference is now made to FIGS. 3A and 3B, showing a method [300] for evaluating compromises in neurological functions associated with Multiple Sclerosis [MS], according to some embodiments of the invention. Method [300] comprises steps of:

-   -   a. providing a system for evaluating compromises in neurological         functions associated with MS [305];     -   b. requesting a subject to fixate on a reference target of a         chart [310];     -   c. for a number of repetitions, presenting a stimulus image in         one of a plurality of zones on the chart to the subject [315];         the subject is requested to remember which zone each stimulus         image appeared and in what order;     -   d. presenting to the subject a cue corresponding to one of the         presented stimulus images [320];     -   e. measuring a saccade of the subject [325] in response to the         step of presenting a cue; the subject is requested to look at         the zone in which was the presented stimulus image corresponding         to the cue;     -   f. repeating steps of presenting a cue and measuring a saccade         [330];     -   g. repeating steps b-f for a number of trials [335];     -   h. calculating one or more of:         -   i. a WM effect [340] (i.e. WM effect is a measure that             increases when WM demand increases. For each cue number, the             WM effect is represented by the ratio between the number of             errors reported by the subject through all the trials, and             the number of trials); and         -   ii. an average saccadic latency [345], saccadic latency             defined as an amount of time for the subject to initiate a             saccade to the zone; and     -   i. reporting one or more of:         -   i. a degree of compromise in working memory [350], with             increased WM effect; and         -   ii. a degree of compromise in executive processes [355],             with increased saccadic latency;         -   wherein the method further comprises additional steps,             performed during the step of presenting a stimulus image             [315]; during which the subject is further requested to look             at the stimulus image;     -   j. the additional steps comprising measuring one or more of:         -   i. an amplitude of pupillary dilatation of the subject             [360];         -   ii. a number of fixations made by the subject on the             stimulus image [365]; and         -   iii. a gaze duration by the subject on the stimulus image             [370].     -   k. the additional steps further comprising calculating and         reporting one or more of:         -   i. a degree of compromise of subcortical processes, with an             unchanged amplitude on pupil dilatation [375];         -   ii. a degree of compromise of executive processes, with             increased number of fixations [380]; and         -   iii. a degree of compromise of executive processes and             working memory, with increased gaze duration [385].

The method employs an intelligent algorithm to analyze the subject, utilizing the following variables:

-   -   a. Total number of ocular fixations of a subject while         performing the n-Back Task.     -   b. Identification Number of n-Back Task Trial (i.e. if there are         20 n-Back Tasks Trials, the 5th trial is identified with the         number 5. The 20th trial is identified with the number 20 etc.)     -   c. Trial Part i.e., 1, 2 and 3.     -   d. Part of the Trial i.e., encoding; retrieval.     -   e. Pupil diameter of the subject while performing n-Back Task.     -   f. Number of blinks coming from the left eye, the right eye or         from both eyes.     -   g. Microsaccades; Factors of Form (FF):         -   i. HEWI: shows the microsacade's height/width relationship.         -   ii. AREA: shows the area of the rectangle in which the             microsaccade is inscribed.         -   iii. LONG: is the longitude of the horizontal-vertical plane             trajectory of the microsaccade.         -   iv. ANG: is the sum of all the angles in the plane             horizontal-vertical plane of the microsaccade.         -   v. AANG: is the sum of all the absolute values of angles in             radians in the plane horizontal-vertical plane of the             microsaccade. These las two FF give an estimation of the             microsaccadic trajectory regularity.         -   vi. MOD and THETA: are the modulus and the angle of the             polar coordinates             -   of the sum of the cartesian coordinates. They give a                 spatial orientation of the microsaccade relative to the                 median of the fixation.         -   vii. TIME: is the time duration in milliseconds of the             microsaccade.         -   viii. VMIN and VMAX: are the minimum and maximum velocities             of the microsaccades in degrees per second.         -   ix. Microsaccade rate: is the instantaneous rate in each             time bin.         -   x. Directional congruency: is the congruency between the             microsaccade direction and the location of the stimulus.     -   h. Eye position coming from the left eye, the right eye or from         both eyes (i.e., abscissa and ordinate coordinate) while         performing the n-Back Task.     -   i. Saccade amplitude while processing the targets.     -   j. Saccade latency.     -   k. Fixation sequence (i.e., ocular behavior) while processing         the targets. The sequence will be available from images, from         matrices, etc.     -   l. Distance between the fixation point of the Right Eye and the         Left Eye while performing the processing targets.     -   m. Filia information of the subject (i.e., age; years of         education; sex; ethnic group; occupation; hours per week of         physical activity).     -   n. Fixation duration while processing targets.     -   o. Gaze duration while processing targets.     -   p. Number of fixations on each target.     -   q. Number of fixations outside each target.

The measurements made while presenting the stimulus image (feature j in method [300]) provides information during encoding, which occurs while the subject identifies the location of the visual stimulus for the first time. In pilot studies made by inventors, subjects with MS were found to be impaired when encoding visual information (e.g., subjects made many fixations on the display). Measurements during encoding are in addition to the measurements taken during recognition, when presented with cues after the visual stimuli are presented as in the study of Fielding et al. (steps a-i in method [300]). Taken together, performance of the subject during both encoding and recognition can help identify additional deficiencies (namely, degrees of compromise of subcortical processes, executive processes, and/or executive processes) and provide greater insight into the condition of the subject than performance during recognition alone.

Reading

Reference is now made to FIGS. 4A and 4B, showing a method for measuring general cognitive performance and for detecting one or more neurological disorders of a subject, by measuring eye movements and/or pupil diameter of the subject while the subject is reading, according to some embodiments of the invention.

Method [400] comprises steps of providing a system for measuring general cognitive performance and for detecting the presence of one or more neurological disorders by measuring eye movements and/or pupil diameter; receiving eye-tracking data and/or pupil diameter data of a subject reading a text; analyzing the eye-tracking data for evidence of one or more neurological disorders; and displaying a report of detection of the neurological disorder(s).

In some embodiments, method [400] comprises steps of counting a total number of ocular fixations of the subject while the subject is reading the text [405]; and reporting that a compromise in attentional processes is detected, if the total number of ocular fixations of the subject when reading the text is higher than for a control group [460].

In some embodiments, method [400] further comprises steps of counting a total number of ocular fixations of the subject while reading the text [405]; counting a number of forward ocular fixations of the subject while reading the text [430]; and reporting that a compromise in working memory is detected, if the number of forward ocular fixations of the subject is higher than for the control group and the number of total ocular fixations of the subject when reading is higher than for the control group [470].

Physiologically, a compromise in working memory is correlated with deterioration in the frontal lobe. In some embodiments, reporting of a compromise in working memory [470] may be used in additional treatment. For example, if neurosurgery is indicated, method [400] may be followed by studying brain imagery of the subject's frontal lobe.

In some embodiments, method [400] comprises steps of counting numbers of ocular fixations by the subject on each word in the text while the subject is reading the text [440]; counting a number of words that the subject fixated on only once [445]; and reporting that a compromise in retrieval memory is detected, if the number of words that subject fixated on only once is lower than for the control group [480].

Physiologically, a compromise in retrieval memory is correlated with deterioration in the temporal lobe. In some embodiments, reporting of a compromise in retrieval memory [480] may be used in additional treatment. For example, if neurosurgery is indicated, method [400] may be followed by studying brain imagery of the subject's frontal lobe.

In some embodiments, method [400] comprises steps of counting a number of multiple ocular fixations of subject while reading the text [450]; and reporting that a compromise in executive processes is detected, if the number of multiple ocular fixations is higher than for the control group [490].

In some embodiments, method [400] comprises steps of computing an average saccade amplitude of the subject from one ocular fixation to a next ocular fixation while reading the text [454]; and reporting that a compromise in executive processes is detected, if the average saccade amplitude is lower than for the control group [491].

In some embodiments, method [400] comprises steps of tracking a pupil diameter of the subject while reading the text [456]; and reporting that a compromise in executive processes is detected, if the pupil diameter of the subject does not show a reduction as advancing in reading the text [492].

Physiologically, a compromise in executive processes is correlated with deterioration in the frontal, temporal, and/or parietal lobes. In some embodiments, reporting of a compromise in executive processes [490-491-492] may be used in additional treatment. For example, if neurosurgery is indicated, method [400] may be followed by studying brain imagery of the subject's frontal, temporal, and/or parietal lobes.

The system and method [400] were tested on 50 Healthy Controls and 50 Mild AD Patients. Both groups read 40 regular sentences.

TABLE 1 Test Control Group AD Group Attentional Processes 520 (21) 882 (317) Executive Processes  14 (8)  37 (6) Working Memory  85 (14)  61 (9) Retrieval Memory  30 (6)  12 (11)

BIBLIOGRAPHY

The above rules are based in part upon findings in the following studies:

-   1. Fernández G, Mandolesi P, Rotstein N P, Colombo O, Agamennoni O,     Politi L E. (2013) Eye movement alterations during reading in     patients with early Alzheimer disease. Invest Ophthalmol Vis Sci.     pii: iovs.13-12877v1. doi: 10.1167/iovs.13-12877. -   2. Fernández G., Manes F., Politi L., Orozco D., Schumacher M.,     Castro L., Agamennoni O., Rotstein N. (2016). Patients with Mild     Alzheimer Disease Fail When Using Their Working Memory: Evidence     from the Eye Tracking Technique. Journal of Alzheimer Disease; 50,     827-828. -   3. Fernández, G., Laubrock, J., Mandolesi P., Colombo O.,     Agamennoni O. (2014) Registering eye movements during reading in     Alzheimer disease: difficulties in predicting upcoming words.     Journal of Clinical and Experimental Neuropsychology; 36, 302-16. -   4. Fernández G., Sapognikoff M., Guinjoan S., Orozco D.,     Agamennoni O. (2016). Word processing during reading sentences in     patients with schizophrenia: evidences from the eyetracking     technique. COMPREHENSIVE PSYCHIATRY; 68, 193-200. -   5. Fernández G, Manes F, Rotstein N, Colombo O, Mandolesi P, Politi     L, Agamennoni O. (2014) Lack of contextual-word predictability     during reading in patients with mild Alzheimer disease.     Neuropsychologia; 62, 143-51. -   6. Fernández G., Schumacher M., Castro L., Orozco D., Agamennoni O.,     (2015). Patients with Alzheimer disease produced shorter outgoing     saccades when reading sentences. Psychiatry Research, 229, 470-478. -   7. Fernández G., Biondi J., Castro S., Agamennoni O. (2017). Pupil     size behavior during online processing of sentences. Journal of     Integrative Neurosciences 15(4) 485-496     Memory Binding

Non-limiting embodiments of the invention are now described in detail.

Reference is now made to FIG. 5 , showing a method [500] for detecting a disorder of memory binding function in a subject, according to some embodiments of the invention.

Method comprises a step [505] of providing a system for detecting a disorder of memory binding function in a subject.

In some embodiments, method [500] comprises a step [510-535] of viewing by a subject of one or more targets; a step [545] of measuring a gaze duration of the subject on each of said targets; a step [550] of calculating an average gaze duration of the targets by the subject; and a step [565] of reporting that a compromise in a target encoding and recognition process is detected in the subject, if an average of the gaze durations of the subject is longer than an average gaze duration for a control group.

In some embodiments, method [500] comprises a step [555] of measuring one or more pupil diameters of the subject while performing activities requiring lower cognitive effort (e.g., recognizing three targets or distinguishing between targets; and a step [570] of reporting that a compromise in cognitive resources is detected in subject [5], if an average pupil diameter of subject [5] while performing the activities requiring a stronger cognitive effort does not show an increase over an average pupil diameter of subject [5] while performing activities requiring lower cognitive effort.

In some embodiments, method [500] comprises a step [560] of counting a number of ocular fixations by subject [5] while viewing the targets [30]; and a step [575] of reporting that a compromise in attentional processes is detected in subject [5], if the number of ocular fixations performed by subject [5] while viewing the targets [30] is higher than for the control group.

BIBLIOGRAPHY

The above rules are based in part upon findings in the following studies:

-   1. Fernández G, Mandolesi P, Rotstein N P, Colombo O, Agamennoni O,     Politi L E. (2013) Eye movement alterations during reading in     patients with early Alzheimer disease. Invest Ophthalmol Vis Sci.     pii: iovs.13-12877v1. doi: 10.1167/iovs.13-12877. -   2. Fernández G., Manes F., Politi L., Orozco D., Schumacher M.,     Castro L., Agamennoni O., Rotstein N. (2016). Patients with Mild     Alzheimer Disease Fail When Using Their Working Memory: Evidence     from the Eye Tracking Technique. Journal of Alzheimer Disease; 50,     827-828. -   3. Fernández, G., Laubrock, J., Mandolesi P., Colombo O.,     Agamennoni O. (2014) Registering eye movements during reading in     Alzheimer disease: difficulties in predicting upcoming words.     Journal of Clinical and Experimental Neuropsychology; 36, 302-16. -   4. Fernández G., Sapognikoff M., Guinjoan S., Orozco D.,     Agamennoni O. (2016). Word processing during reading sentences in     patients with schizophrenia: evidences from the eyetracking     technique. COMPREHENSIVE PSYCHIATRY; 68, 193-200. -   5. Fernández G, Manes F, Rotstein N, Colombo O, Mandolesi P, Politi     L, Agamennoni O. (2014) Lack of contextual-word predictability     during reading in patients with mild Alzheimer disease.     Neuropsychologia; 62, 143-51. -   6. Fernández G., Schumacher M., Castro L., Orozco D., Agamennoni O.,     (2015). Patients with Alzheimer disease produced shorter outgoing     saccades when reading sentences. Psychiatry Research, 229, 470-478. -   7. Fernández G., Biondi J., Castro S., Agamennoni O. (2017). Pupil     size behavior during online processing of sentences. Journal of     Integrative Neurosciences 15(4) 485-496. -   8. Biondi J., Fernández G., Castro S., Agamennoni O. (2018).     Eye-movement behavior identification for Alzheimer Disease     diagnosis. Journal of Integrative Neurosciences (in Press). -   9. Fernández, Orozco, Agamennoni, Schumacher, Sañudo, Biondi, Parra.     (2018). Visual Processing during Short-Term Memory Binding in Mild     Alzheimer's Disease. J Alzheimers Dis.; 63(1):185-194. doi:     10.3233/JAD-170728.     Parkinson Disease (PD) and Attentional Deficit Hyperactive Disorders     (ADHD)

Reference is now made to FIGS. 6A and 6B showing a method for detecting one or more cognitive, neurological and behavioral impairments of a person, by measuring eye movements and/or pupil diameter of the person while the person is performing the visual test, according to some embodiments of the invention.

Method [600] comprises steps of providing a system for detecting the presence of one or more cognitive impairments and neurological disorders by measuring eye movements while a person is visualizing, recognizing, maintaining, controlling, inhibiting and sequencing targets; receiving eye-tracking data of a person visualizing, recognizing, maintaining, controlling, inhibiting and sequencing targets; analyzing the eye-tracking data for evidence of one or more cognitive impairments and neurological disorders; and displaying a report of detection of the cognitive impairments and neurological disorder(s).

In some embodiments, method [600] comprises steps of counting a total number of ocular fixations [615] of the person while the person is performing the visual test; and reporting that a compromise in attentional, executive and inhibitory processes is detected, if the number of ocular fixations of the person is higher than for a control group.

In some embodiments, method [600] comprises steps for calculating the saccade average speed [620] of the subject [5] from one target to the other one, while the subject [5] is performing the visual test; reporting that a compromise in executive functions is detected, if the saccade average speed that person did is lower than for the control group.

Physiologically, a slower saccade speed is correlated with deterioration in frontal eye fields, basal ganglia and superior colliculus. In some embodiments, reporting of a compromise in saccade speed may be used in additional treatment.

In some embodiments, method [600] comprises steps of counting a number of correct target recognitions of person while performing the visual test [625]; and reporting that a compromise in working memory is detected, if the number of correct target recognitions is lower than for the control group.

Physiologically, a compromise in working memory is correlated with a deterioration in Prefrontal Cortex and in the Posterior Parietal Cortex. In some embodiments, reporting of a compromise in working memory, inhibition processes and mental flexibility may be used in additional treatment.

In some embodiments, method [600] comprises steps of computing an average saccade amplitude from one ocular fixation to a next ocular fixation [630]; and reporting that a compromise in executive processes is detected, if the average saccade amplitude is lower than for the control group.

In some embodiments, method [600] comprises steps of tracking a pupil diameter of the person while performing the visual test [640]; and reporting that a compromise in attentional processes is detected, if the pupil diameter of the subject does not show an increase as advancing in performing the visual test.

Physiologically, a compromise in attentional processes is correlated with deterioration in the locus coeruleus, the noradrenergic system and in the superior colliculus. In some embodiments, reporting of a compromise in the executive processes may be used in additional treatment.

In some embodiments, method [600] comprises steps of computing the total time spent by the person while performing the visual trial [635]; and reporting that a compromise in attentional processes is detected, if the total time needed for performing the trial is major that the reported for the control group.

Physiologically, a compromise in attentional and inhibitory processes and in mental flexibility is correlated with deterioration in the prefrontal cortex, the posterior parietal cortex, the prefrontal striatal cerebellar and prefrontal striatal thalamic circuits. In some embodiments, reporting of a compromise in executive processes may be used in additional treatment.

In some embodiments, method [600] comprises steps of calculating fixation durations on targets of person while performing the visual test [645]; and reporting that a compromise in working memory is detected, if the fixation duration on targets is lower than for the control group.

Physiologically, a compromise in attentional and inhibitory processes and in mental flexibility is correlated with deterioration in the prefrontal cortex, the frontal eye fields and in the dorso-parietal cortex. In some embodiments, reporting of a compromise in executive processes may be used in additional treatment.

The method employs an intelligent algorithm to analyze the subject, utilizing the following variables:

-   -   a. Total number of ocular fixations of a subject while         performing the Visual Test.     -   b. Identification Number of each target depending of its place         in the labyrinth or maze     -   c. Pupil diameter of the subject while performing the visual         Test.     -   d. Number of blinks coming from the left eye, the right eye or         from both eyes.     -   e. Microsaccades; Factors of Form (FF):         -   i. HEWI: shows the microsacade's height/width relationship.         -   ii. AREA: shows the area of the rectangle in which the             microsaccade is inscribed.         -   iii. LONG: is the longitude of the horizontal-vertical plane             trajectory of the microsaccade.         -   iv. ANG: is the sum of all the angles in the plane             horizontal-vertical plane of the microsaccade.         -   v. AANG: is the sum of all the absolute values of angles in             radians in the plane horizontal-vertical plane of the             microsaccade. These las two FF give an estimation of the             microsaccadic trajectory regularity.         -   vi. MOD and THETA: are the modulus and the angle of the             polar coordinates of the sum of the cartesian coordinates.             They give a spatial orientation of the microsaccade relative             to the median of the fixation.         -   vii. TIME: is the time duration in milliseconds of the             microsaccade.         -   viii. VMIN and VMAX: are the minimum and maximum velocities             of the microsaccades in degrees per second.         -   ix. Microsaccade rate: is the instantaneous rate in each             time bin.         -   x. Directional congruency: is the congruency between the             microsaccade direction and the location of the stimulus.     -   f. Eye position coming from the left eye, the right eye or from         both eyes (i.e., abscissa and ordinate coordinate) while         performing the visual Task.     -   g. Saccade amplitude while processing the targets.     -   h. Saccade latency.     -   i. Fixation sequence (i.e., ocular behavior) while processing         the targets. The sequence will be available from images, from         matrices, etc.     -   j. Distance between the fixation point of the Right Eye and the         Left Eye while performing the processing targets.     -   k. Filia information of the subject (i.e., age; years of         education; sex; ethnic group; occupation; hours per week of         physical activity).     -   l. Fixation duration while processing targets.     -   m. Number of fixations on each target.     -   n. Number of fixations outside each target.     -   o. Total visual Task time (i.e., how much time spent the subject         for performing the entire trial).

This method [600] was tested on subjects with PD and ADHD and compared to healthy controls:

TABLE 2 Parkinson Disease CONTROL PM Mean GAZING (MS)    283 (±42.4)    359.2 (±29.5) % Correct Fixation  95% (±3)    81% (±6) ADHD CONTROL ADHD Mean GAZING (MS)    283 (±42.4)    370.3 (±33.1) % Correct Fixation  95% (±3)    73% (±7) 

The invention claimed is:
 1. A system for detecting one or more cognitive disorders that include frontal, temporal, and or parietal lobes alterations in a subject by measuring eye movements; said measuring of eye movements performed while said subject is reading; said system comprising a. an eye tracker, configured to monitor eye movements of a subject while the subject is reading a text; b. a processor, configured to receive data from said eye tracker while said subject is reading said text; and c. a display means configured to display a test report received from said processor; wherein said processor is further configured to analyze the eye-tracking data for evidence of one or more cognitive compromises and to report, in said test report, a detection of a measure of cognitive compromises in specific cognitive domains that include at least one of working memory, retrieval memory, executive and attentional processes of said subject.
 2. The system of claim 1, wherein said processor is further configured, upon receiving said eye-tracking data from said eye tracker, to a. count a total number of ocular fixations of a subject while reading the text; and b. if said total number of ocular fixations of a subject when reading is higher than for a control group, then report in said test report that a compromise in attentional processes is detected.
 3. The system of claim 1, wherein said processor is further configured, upon receiving said eye-tracking data from said eye tracker, to a. count a number of forward ocular fixations of said subject while reading said text; and b. if said number of forward ocular fixations of said subject is lower than for said control group, and said number of ocular fixations of a subject when reading is higher than for said control group, then report in said test report that compromises in working memory is detected.
 4. The system of claim 1, wherein said processor is further configured, upon receiving said eye-tracking data from said eye tracker, to a. count a number of words that said subject fixated on only once while reading said text; and b. if said number of words that said subject fixated on only once is lower than for said control group, then report in said test report that a compromise in retrieval memory is detected.
 5. The system of claim 1, wherein said processor is further configured, upon receiving said eye-tracking data from said eye tracker, to a. count a number of multiple ocular fixations of said subject while reading said text; and b. if said number of multiple ocular fixations is higher than for said control group, then report in said test report that a compromise in executive processes is detected.
 6. The system of claim 1, wherein said processor is further configured, upon receiving said eye-tracking data from said eye tracker, to a. compute an average saccade amplitude from one ocular fixation to a next ocular fixation; and b. if said average saccade amplitude from one ocular fixation to a next ocular fixation is lower than for said control group, then report in said test report that a compromise in executive processes is detected.
 7. The system of claim 1, further comprising a means for measuring a pupil diameter of said subject, wherein said processor is further configured to a. track said pupil diameter of said subject reading said text; and b. if said pupil diameter of said subject does not show a reduction as advancing in reading said text, then report in said test report that that a compromise in executive processes is detected.
 8. A system for detecting one or more neurological disorders and to check cognitive compromises in a subject by measuring eye movements and pupil behavior and applying an intelligent algorithm, said measuring of eye movements performed while said subject is reading; said system comprising: a. an eye tracker, said eye tracker configured to monitor eye movements and pupil behavior of a subject while the subject is reading a text; b. a processor, said processor configured to receive data from said eye tracker while said subject is reading said text; c. an intelligent algorithm for learning, identifying, typifying and classifying eye movements features in pathologies and within pathologies; and d. a display means, said display configured to display the output of said intelligent algorithm on a test report; wherein said processor is further configured to analyze eye tracking data for evidence of one or more neurological disorders and from cognitive compromises and to report, in said test report, a detection and classification of said one or more neurological disorders and cognitive compromises of said subject both, between and within pathologies.
 9. The system of claim 8, wherein said processor is further configured, upon receiving said eye-tracking data from said eye tracker, to identify and classifying eye movement features and pupil behavior during reading the text providing an output of the classifier for reporting in the test report a subject's cognitive performance and/or pathological index classification (i.e, the pathology that correspond to the subject because his/her eye movement features); and a compound value within the pathology (i.e., the level of cognitive, behavioral and biological compromise that the subject shows within a particular pathology).
 10. The system of claim 8, wherein said intelligent algorithm is configured to read at least one input, said input selected from a group consisting of: a. Index of total number of ocular fixations of a subject while reading the text; b. Index of forward ocular fixations of the subject while reading the text; c. Index of words that the subject fixated on only once while reading the text d Index of multiple ocular fixations of the subject while reading the text e. Average saccade amplitude from one ocular fixation to a next ocular fixation f. Pupil diameter of the subject reading the text g. Index of blinks coming from the left eye, the right eye or from both eyes; h. Microsaccades' Factors of Form (FF): i. HEWI: shows the micro-saccade's height/width relationship; ii. AREA: shows the area of the rectangle in which the micro-saccade is inscribed; iii. LONG: is the longitude of the horizontal-vertical plane trajectory of the micro-saccade; iv. ANG: is the sum of all the angles in the plane horizontal-vertical plane of the micro-saccade; v. AANG: is the sum of all the absolute values of angles in radians in the plane horizontal-vertical plane of the micro-saccade; These last two vi. FF gives an estimation of the micro-saccadic trajectory regularity; vii. MOD and THETA: are the modulus and the angle of the polar coordinates of the sum of the cartesian coordinates; They give a spatial orientation of the micro-saccade relative to the median of the fixation; viii. TIME: is the time duration in milliseconds of the micro-saccade; ix. VMIN and VMAX: are the minimum and maximum velocities of the micro-saccades in degrees per second; x. Micro-saccade rate is the instantaneous rate in each time bin; xi. Directional congruency: is the congruency between the micro-saccade direction and the location of the stimulus; i. Eye position coming from the left eye, the right eye or from both eyes (i.e., abscissa and ordinate coordinate) during reading the text; j. Fixation sequence (i.e., ocular behavior) during reading the text; The sequence will be available from images, from matrices, etc; k. Distance of separation between ocular fixations during reading the text; l. Filia information of the subject (i.e., age; years of education: sex; ethnic group, occupation; hours per week of physical activity); m. Total reading time (i.e., the time that the subject spent when reading the text).
 11. A method for evaluating compromises in neurological functions associated with Multiple Sclerosis [MS], said method comprising steps of: a. providing a system for evaluating compromises in neurological functions associated with MS; b. requesting a subject to fixate on a central fixation cross surrounded by boxes in an upper right, lower right, upper left and lower left zones; c. for a number of repetitions, presenting a stimulus image in one of the zones to the subject; the subject is requested to remember which zone each stimulus image appeared and in what order; d. presenting to the subject a cue corresponding to one of the presented stimulus images e. measuring a saccade of the subject in response to said step of presenting a cue; the subject is requested to look at the zone in which was the presented said stimulus image corresponding to said cue; f. repeating steps of presenting a cue and measuring a saccade; g repeating steps b-e for a number of trials; h. calculating at least one of the following: i. a WM effect, wherein the WM effect is a measure that increases when WM demand increases such that for each cue number, the WM effect is represented by the ratio between a number of errors reported by the subject through all trials, and a number of trials; and ii. an average saccadic latency, saccadic latency defined as an amount of time for said subject to initiate a saccade to said zone; iii. reporting one or more of iv. a degree of compromise in working memory, with increased said WM effect; and ii. a degree of compromise in executive processes, with increased said saccadic latency; h. wherein said method further comprises additional steps comprising measurements performed during said step of presenting a stimulus image, during which said subject is further requested to look at said stimulus image; said measurements comprising measuring at least one of the following: i. a lack in an amplitude of pupillary dilatation of the subject as the cognitive load increases; ii. a number of fixations made by the subject on said stimulus image; and iii a gaze duration by said subject on said stimulus image; and k. said additional steps further comprising calculating and reporting at least one of the following: i. a degree of compromise of subcortical brain areas, with a lack in the amplitude of pupillary dilatation as the cognitive load increases; ii. a degree of compromise of executive processes, with increased said number of fixations; and iii. a degree of compromise of executive processes and working memory, with increased said gaze duration.
 12. The method of claim 11, wherein the reference target is at a central position of said visual stimuli and said plurality of zones are disposed around said reference target.
 13. The method of claim 11, wherein said cue is disposed at a position of said reference target.
 14. The method of claim 11, said errors defined as eye movement towards a location other than the correct zone and/or no saccade initiated within a time limit.
 15. The method of claim 11, wherein a cue corresponding to a first presented stimulus is excluded from the presented cue numbers.
 16. The method of claim 11, wherein a saccade is included in said step of calculating said WM effect and said saccadic latency only if said saccade is initiated more than a minimum saccade latency after said step of presenting the cue number.
 17. The method of claim 11, wherein said saccade is excluded from calculating WM if: no saccade to one of said zones is made within a time limit, failing to maintain said fixation on the reference target before onset of a saccade to one of said angular zones, and blinking causing eye motion to be indeterminate.
 18. A method for detecting the presence of one or more cognitive compromises in specific cognitive domains that include at least one of working memory, retrieval memory, executive processes and attentional processes in a subject by measuring eye movements of said subject; said measuring of eye movements performed while said subject is reading; said method comprising steps of: a. providing the system for detecting one or more neurological disorders of claim 1; b. receiving eye-tracking data and/or pupil diameter data of a subject while the subject is reading a text; wherein said method further comprises steps of analyzing said eye-tracking data and/or pupil diameter data for evidence of one or more cognitive compromises and displaying a report of a detection of said cognitive compromises.
 19. The method of claim 18, further comprising steps of: a. counting a total number of ocular fixations of said subject while said subject is reading said text; and b. if said total number of ocular fixations of said subject while reading said text is higher than for a control group, then reporting that a compromise in attentional processes is detected.
 20. The method of claim 18, further comprising steps of: a. counting a total number of ocular fixations of said subject while said subject is reading said text; b. counting a number of forward ocular fixations of said subject while said subject is reading said text; and c. if said number of forward ocular fixations of said subject while reading said text is lower than for said control group; and said number of ocular fixations of a subject when reading is higher than for said control group, then reporting that a compromise in working memory is detected. 